A frame for a motor vehicle made up of the union of a plurality of extruded elements comprises a plurality of linear bars, which have a constant cross section, are obtained by extrusion, and are joined to one another by means of welding at structural nodes defined by jointing bodies provided with pockets for housing the ends of the linear bars themselves.
Currently, in a frame for a motor vehicle obtained by the union of a set of extruded metal elements, all the elements of the frame are obtained by extrusion, with the exception of the jointing bodies (i.e., the points in which a number of elements of the frame are joined), which are obtained by casting in so far as they have a complex shape that cannot be obtained by extrusion. However, the jointing bodies obtained by casting prove heavy and costly (particularly in the case of limited production of sports cars) as a result of the high costs for fabrication of the dies. Furthermore, once a die for a jointing body has been made, it is difficult to make any modification to the die itself to provide constructional variants of the jointing body itself.